Fix for bz#13658 - using fsincos on x86-64

[Joseph S. Myers]

On Wed, 7 Mar 2012, Andreas Jaeger wrote:

> So, the result has nothing to do with the expected result. The test 
> passes on x86-64.
> 
> I could add the testcase and the fix for x86-64 and not run it on i386 - 
> or only run it on x86-64. What do you propose?

Is this failing on i386 with sysdeps/i386/fpu/s_sincos.S removed?  Because 
I'd expect both x86-64 and i386 to need the same fix at the same time.

Actually it looks like s_sincos.c is using __sin and __cos - meaning that 
i386 would need s_sin.S and s_cos.S removed as well.  But I'd guess that 
sin and cos have the same problems for large inputs (insufficiently 
accurate range reduction) as sincos and so that making i386 follow x86-64 
in using the generic dbl-64 versions of those functions would also be an 
improvement.

(Eventually all of sin, cos, tan, sincos should have testcases for large 
inputs covering all of float, double, long double - but that will need 
quite a few more fixes including ldbl-96 implementations of a few 
functions.  So I think we should get in the minimum that can be done 
incrementally, then follow up later with more fixes and tests for more 
functions, for more input formats.)

-- 
Joseph S. Myers
joseph@codesourcery.com